2 BULLETIiS" 702, U. S. DEPAETlviENT OF AGRICULTURE. 



of eggs to accuracy in candling; (3) the relative occurrence of bad 

 eggs not to be found by candling; (4) the comparative degree of 

 accuracy of skilled and unskilled candling creAvs. 



PLAN AND SCOPE OF INVESTIGATION. 



The investigation was carried on in commercial packing houses 

 located in the Middle West and in distributing houses in the East. 

 During warm weather the eggs under observation were kept in chill- 

 rooms, according to commercial practice, at a temperature of 32° to 

 40° F., from the time of receipt until the time of candling. This 

 chilling serves to check deterioration and to restore to some extent 

 the natural firmness of the egg substance. For grading, the eggs 

 were removed to candling rooms which were refrigerated to a tem- 

 perature of 50° to 55° F. 



After the eggs had been candled they were opened and graded in 

 accordance with the standards for the preparation of frozen and 

 dried eggs. The number of bad eggs not detected by candling was 

 determined by observing the appearance and odor when opened in 

 glass cups. The conclusions reached in this study were drawn from 

 eggs so handled, which had been graded by commercial candlers ac- 

 cording to trade routine. It was the endeavor to grade as edible all 

 eggs with whole yolks which were not seeping, not heavil}^ mottled, 

 nor stuck to the shell, and which contained neither blood nor visible 

 mold infection. Out of the shell an egg was graded as edible if the 

 yolk was whole, the white clear and not colored, and the odor good. 

 If the yolk membrane did not break until the egg was dropped in the 

 grading cup, it was considered edible. The usual speed of candling 

 was not changed, because it was desired to determine the accuracy of 

 the process under commercial conditions. 



The eggs rejected by the candlers as unfit for food purposes were 

 critically recandled to find any good eggs that might be present and 

 the reason for their not being found on the first candling. In cases 

 of doubt the eggs were opened. It was not considered necessary or 

 desirable to check the candling of the unquestionably bad eggs by 

 breaking. 



The studies reported were made on 187 cases (30 dozen each) of 

 .storage-packed eggs, 170.2 cases of refrigerator or cold-storage eggs, 

 174.4 cases of breaking stock, and 1,521,7 cases of rejected eggs, that 

 is, " rots and spots." The observations on the storage-packed and re- 

 frigerator or cold-storage eggs were made from samples having a com- 

 parable history. On arrival in the East of carload shipments of com- 

 mercial storage-packed eggs, from 8 to 20 cases were examined within 

 a comparatively short period after receipt. About the same number 



